Sacramento daily record-union. [volume] (Sacramento [Calif.]) 1875-1891, 1887-01-15
GRAVEL MINING.
THE DEPOSITS IN THE FOOTHILLS
OF THE SIERRAS.
are Worked-Yield of Gold
-Extent-Etc.

| are Worked-Yield of Gold
-Extent-Etc.
| The grayel-mining region proper Of Cali
| fornia is on the western slope and foothills
of the Sierras beginning with Mariposa
county OF the south, and extending north
into Plumas. The. importance of the
gravel deposits increases as we 60 from
Tuolumne TO Calaveras, and thence to A ma
dor. E. Dorado, Placer, Nevada and Sierra
are the great mining counties, and there is
a gradual falling of in Butte and Plumas
where the mines are nearing exhaustion.
This region OF auriferous gravel is also
traversed by numerous quartz veins. There
the metal gold and the mineral quartz. A
large portion of the gold obtained through
out the world comes from the debris OF
such veins and rocks formed by the opera
ton OF those eroding and disintegrating
agencies which are and have been at work
| forever since rocks began to be formed.
| The geographical range of the gravel is
| much more extensive than that of the
quartz veins-at least of such as are pro-
ductive.
| Gold was discovered by Marshall at Co
| Lorna in FL Dorado county, January 10, 1913.
| The discovery was almost in the center OF
the great auriferous gravel deposit. In the
case of ordinary gold washing it is neces-
sary.to separate the gold from the sand and
| gravel. The simplest implement for effect
| ing this is the pan, a sheet-iron or tin YES
sci with a fat bottom, a foot or more in
| diameter. Il is partly filed with the ma
| terial 10 be operated on, and then, with the
repeated additions OF water, shaken with
peculiar motion not easily described, the
| earthly articles being allowed to pass over
| the edge OF the utensil, until finally naught
but the precious metal remains. The next
| most simple instrument used in gold wash
! ing is the rocker " or " cradle wooden
trough about forty inches long, twenty
wide, and hopper twenty inches square,
| the bottom of which is piece OF sheet
iron pierced with holes half an inch in
diameter. The long tom is sort OF
enlarged cradle, without the rocking mo-
| ton. These implements were exten-
sively used in 40 and the early
| tifties, but long since gave way
to better and more economical
| devices. The so-called sluice" Is almost
universally employed, whether the opera
tions carried on be on a large or a small
| scale The object OF the sluice is TO imi-
| tate nature as closely as possible, by allow
| ing auriferous sands and gravelS to be car
RED by water over the bottom of a box
provided with rifles which detain the gold
| as il settles 10 the bottom. A great guam
| tity of material can thus be washed, be-
cause the sluice can be made very wide and
| the current allowed to flow rapidly The
| - 10 h n nf mn
- would otherwise give rise is prevented
| by making the sluice very long, that in the
| North Bloomfield mine being 1,S00 feet in
| length. The rifles which serve 10 detain
| the gold are made OF various materials, and
| arranged IL different ways. Square blocks
OF pine wood. laid side by side, SO as to
have spaces of an inch or inch and half
| between them are much in use. Some use
| the longitudinal rifles, others use round
stones instead of blocks. The rifles are
also charged with quicksilver. The
'sluice seems 10 have been introduced II
1851.
IN 1S49 and 1850 at least $4,000 miners
| were at WORK on the tanks OF the Sierras,
al least nine-tenths Of them engaged in
| what is called river mining. that is, wash
| ing the accumGlations Of sand and gravel
along the channels OF the present rivers, or
| in their immediate vicinity, This was
done either by attacking the e bars, as the
sand and gravel banks along the river are
called. during the season OF low water, or by
fuming the streams; that is taking up
the water in wooden fumes constructed
| along the banks for some distance so as to
| leave the bed OF the river dry and accessible
az all points Such localities, on the prin-
cipal streams IN the heart of the gold re-
gion, were often found exceedingly rich.
and they have all been washed over and
over. N some cases q dozen times, until
they have become almost exhausted, so as
70 De no longer worth working, except here
and there party OF Chinese miners, con-
tent with very moderate gains may find il
worth while 70 attack them. Along the
sides OF the canyons, i'll rich districts the
cTeTices between the projecting edges OF the
slate, in the ravines or so-called gulches,
leading down 20 the rivers, were, dur
ing the early years OF gold mining,
scraped out with knives and the detritus
thus obtained PANIED out, often yielding
large returns. From the spring of 184S to
1851 nearly all the mining was prosecuted
as has been described, that in the river beds
being called wet diggings" and that in
the ravines =" dry diggings." AS localities
of that character could not furnish room
for all, search began to be made on higher
ground. away from the rivers, and quartz
mines were opened, the outcrops of many
Of the veins being very conspicuous. The
diggiDgs gradually extended 10 the flats,
and to higher ground where the gravel was
not so rich as in the river beds more OF the
materia! had 10 be handled in order to Sc
cure the same amount of gold. The neces-
sity for improvement in washing facilities
was apparent. This led to the invention
of the so-called hydraulic method OF
I.+o
and IS to be credited to Edward E. Matte
son, native of Sterling, Connecticut.
This was improved upon from time TO time
until It was apparently perfected. 1t, with
its giant nozZles tore down mountains,
would attack three hundred-foot bank OF
gravel as man-of-war would lombard a
citv. This became so great q mover OF
earth that the valley people complained 1t
would FL the rivers with debris, destroy
navigation and work ruin upon the valleys.
Long litigation ensued, and resulted ID the
enjoinment-ef all mines worked by the ny
draulic process. This decision of the Court
shut down g score of mines that were annu-
ally taking out millions Of gold, and the
working of which constituted the prosper
ity of the counties in which they were To-
Gated.
These detrital gravel deposits are not dis
tributea over the tanks Of the Sierra an
any such way as they would have been if
they were the result OF the action of the
sea. On the contrary, there isreason to be
Eeve that they consist of materials which
have been brought down from the noun
tain heights above and deposited in pre-
existing valleys. Sometimes very narrow
aocumulations, simple beds of ancient
rivers, and at other times in wide lake-like
| expansions Of former water-courseS; and
this, under the action of causes similar TO
those now existing, but probably of con
siderably greater intensity. This deposition
of detritus, for the most part auriferous,
| tnok Mace during the later pliocene epoch.